/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package io.netty.buffer;

import io.netty.util.internal.PlatformDependent;

/**
 * Special {@link SwappedByteBuf} for {@link ByteBuf}s that are backed by a {@code memoryAddress}.
 */
final class UnsafeDirectSwappedByteBuf extends AbstractUnsafeSwappedByteBuf {

  UnsafeDirectSwappedByteBuf(AbstractByteBuf buf) {
    super(buf);
  }

  private static long addr(AbstractByteBuf wrapped, int index) {
    // We need to call wrapped.memoryAddress() everytime and NOT cache it as it may change if the buffer expand.
    // See:
    // - https://github.com/netty/netty/issues/2587
    // - https://github.com/netty/netty/issues/2580
    return wrapped.memoryAddress() + index;
  }

  @Override
  protected long _getLong(AbstractByteBuf wrapped, int index) {
    return PlatformDependent.getLong(addr(wrapped, index));
  }

  @Override
  protected int _getInt(AbstractByteBuf wrapped, int index) {
    return PlatformDependent.getInt(addr(wrapped, index));
  }

  @Override
  protected short _getShort(AbstractByteBuf wrapped, int index) {
    return PlatformDependent.getShort(addr(wrapped, index));
  }

  @Override
  protected void _setShort(AbstractByteBuf wrapped, int index, short value) {
    PlatformDependent.putShort(addr(wrapped, index), value);
  }

  @Override
  protected void _setInt(AbstractByteBuf wrapped, int index, int value) {
    PlatformDependent.putInt(addr(wrapped, index), value);
  }

  @Override
  protected void _setLong(AbstractByteBuf wrapped, int index, long value) {
    PlatformDependent.putLong(addr(wrapped, index), value);
  }
}
